XRAY - Model racing cars

What are the effects when changing to lighter or heivier viscosity oil in the front diff?
I'm guessing that lighter=more steering?

there is a good guide in the nt1 set up book which is free to download on the main xray site

Heavier = less turn in, more on-power steering. More straight line traction.

Ligther = more turn in, quicker direction change but less steering out of corners.

hey, is it better to keep more traction in the front or the rear? i have seen some set up with heavier diff oil on the front than the rear diff? why dont get it heavier in the rear than the front?

hey how often you should replace diff oil?

The front diff needs to be heavier since you don't want a lot of diff action on-power. It will upset the balance of the car quite a lot.

Diff oil is not one of those thinghs which need to be checkes very frecuently. If you go for testing for sure they will last the whole weekend. In week en races I set the diffs on friday and leave them until Sunday without any problem. Nevertheless you should always check and maybe replace the o-ring when rebuilding the diff.